在 RubyonRails 中解析字符串就像解析查询字符串一样

我有一条这样的线:

"foo=bar&bar=foo&hello=hi"

Ruby on Rails 是否提供了方法来像解析查询字符串一样解析它，所以我得到了这样一个散列:

{
:foo => "bar",
:bar => "foo",
:hello => "hi"
}

还是要我自己写？

剪辑

请注意，上面的字符串不是来自 URL 的真正的查询字符串，而是存储在来自 Facebook Connect 的 cookie 中的字符串。

44878 次浏览
小开

The

CGI::parse("foo=bar&bar=foo&hello=hi")

Gives you

{"foo"=>["bar"], "hello"=>["hi"], "bar"=>["foo"]}

Edit: As specified by Ryan Long this version accounts for multiple values of the same key, which is useful if you want to parse arrays too.

Edit 2:

As Ben points out, this may not handle arrays well when they are formatted with ruby on rails style array notation. The rails style array notation is: foo[]=bar&foo[]=nop. That style is indeed handled correctly with Julik's response.

This version will only parse arrays correctly, if you have the params like foo=bar&foo=nop.

小开
最佳答案

The answer depends on the version of Rails that you are using. If you are using 2.3 or later, use Rack's builtin parser for params 

 Rack::Utils.parse_nested_query("a=2") #=> {"a" => "2"}

If you are on older Rails, you can indeed use CGI::parse. Note that handling of hashes and arrays differs in subtle ways between modules so you need to verify whether the data you are getting is correct for the method you choose.

You can also include Rack::Utils into your class for shorthand access.

小开

Edit : as said in the comments, symolizing keys can bring your server down if someone want to hurt you. I still do it a lot when I work on low profile apps because it makes things easier to work with but I wouldn't do it anymore for high stake apps

Do not forget to symbolize the keys for obtaining the result you want

Rack::Utils.parse_nested_query("a=2&b=tralalala").deep_symbolize_keys

this operation is destructive for duplicates.

小开

If you talking about the Urls that is being used to get data about the parameters them

> request.url
=> "http://localhost:3000/restaurants/lokesh-dhaba?data=some&more=thisIsMore"

Then to get the query parameters. use

> request.query_parameters
=> {"data"=>"some", "more"=>"thisIsMore"}
小开

If you want a hash you can use

Hash[CGI::parse(x).map{|k,v| [k, v.first]}]

提交答案